Dialkyl esters of glycol polycarboxylic acid esters



Patented Jan. 6, 1953 DIALKYL ESTERS OF GLYCOL POLYCAR- BOXYLIC ACID ESTERS Edward S. Blake, Lexington, Mass., assignor to Monsanto Chemical Company, St. Louis, Mo., a

corporation of Delaware Original application June 11, 1947,

No Drawing.

Serial No. 754,057.

3 Claims.

This invention relates to alkyl esters of glycol bis aliphatic polycarboxylic acid esters.

The compounds of this invention are polyesters derived from polycarboxylic acids and monohydric alcohols. Because of the complex nature of their chemical composition, it is not possible to state their chemical structure with absolute certainty. The products may be mixtures of related materials. Separation and isolation of all the components has not yet been achieved but for most purposes the crude reaction products are entirely satisfactory. Therefore, the invention also relates to the crude reaction products of polyester materials produced by the methods herein described.

The general formula of the compounds of this invention is dride, a typical representative of a suitable anhydride, reacts vigorously with monoethylene glycol. It is believed that the reaction proceeds mainly in accordance with the following equation:

I! CHE-O nooo-onnooo CgH40.CO.CgH -COOH The dicarboxylic acid ester so produced is then treated with a monohydric alcohol to esterifyone or both of the carboxyl groups.

Alternatively, the anhydride may first be condensed with a monohydric alcohol. Thus, again employing succinic anhydride as illustrative of a polycarboxylic anhydride and employing oleyl alcohol as illustrative of a monohydric alcohol,

Divided and this application February 4, 1950, Serial No. 142,540

:satisfactory alcohols are allyl alcohol,

the reaction is represented by the following equa tion:

The monocarboxylic acid ester is then reacted with a glycol so as to leave at least one hydroxyl group of the latter free The monohydric ester alcohol is then reacted with a further quantity of anhydride to obtain the final product in accordance with the equation:

Polycarboxylic acids instead of the anhydrides may be used but the reaction with anhydrides provides a convenient method of controlling the reaction so as to esterify only one carboxyl group at a time, thereby permitting a second carboxyl group to be esterified with a different alcohol as required for the preparation of the new prod- -ucts.

A wide variety of alcohols have been successfully employed for the preparation of the polyesters of this invention. Typical examples of ethyl hexanol, stearoyl alcohol, oleyl or A octadecenyl alcohol, linoleyl or A A A octadecatrienyl alcohol, clupanodony1 alcohol, a 22 carbon non-conjugated alcohol containing 6 double bonds derived from menhaden oil, and erucyl or A 3 docosenyl alcohol. The long chain unsaturated alcohols are available from the reduction of fatty acid esters, as for example olive oil, linseed oil, tung oil, rapeseed oil, and marine oils.

The examples below illustrate the preparation of the new polyesters and are not to be taken as limitative of the invention.

Mono oleyl succinate 100 C. The mixture was then heated at 100-103 for ten hours and the solvent removed by distillation under reduced pressure. Moreparticularly, the mixture was heated up to 130 C./1-2 The residuezwas Oleyl beta hydroxy ethyl succinate Mono oleyl succinate, 161.9 parts by weight or 0.44 molecular proportion, and ethylene glycol, 124 parts by weight or 2.0 molecular proportions were mixed with toluene sufiicient to imparta refluxing temperature of 140-150 C. The mixture was heated at refluxing temperature for seven hours, and then an additional 100 parts by weight of ethylene glycol and more toluene were added to impart a refluxing temperature of PTO-180 C., and the mixture heated for nine hours at PTO-180 C. During the reaction water and glycol were removed from the reaction zone and finally all the excess glycol was removed by vacuum stripping up to 160 C./1 mm. The residue was diluted with a solvent, as for example acetone, and filtered through a bed of clay after which the solvent was removed by vacuum stripping. The product had a neutralization number of zero indicating that complete esterification had been effected. It was a liquid at ordinary temperatures but solidified on refrigeration. The hydroxyl groups available for further esterification were somewhat more than the calculated value, probably due to the presence of free alcohol constituents not removed by the vacuum stripping. Thus, the Zerewitinoff method for determination of hydroxyl groups by methane evolution gave 27.3 cc. of methane as compared to a calculated value of 22.5 cc.

EXAMPLE I Into a container of suitable capacity provided with a reflux condenser there was charged substantially 69.4 parts by weight of the above oleyl beta hydroxy ethyl succinate and parts by weight of succinic anhydride together with benzene in amount sufiicient to impart a refluxing temperature of slightly above 100 C. The mixture was heated at about 105 C. for ten hours, then diluted with a mixture of petroleum ether and benzene and filtered through a bed of clay. The solvent was removed by distillation under reduced pressure. The product obtained as a residue was a yellow brown liquid readily soluble in mineral oil fractions and was believed to comprise mainly the mono oleyl ester of ethylene diacid succinate.

Mono oleyl maleate Into a container of suitable capacity there was charged 303.5 parts by weight (substantially 1.02 molecular proportions) of 90% oleyl alcohol and 98 parts by weight (substantially 1.0 molecular proportion) of maleic anhydride. The reactants were stirred and heated at 45-60 C. for nineteen hours. Temperatures of 100 C. and above are to be avoided as there isthen considerable water split out, probably as the result of the formation 4 of the neutral ester. The reaction mixture was cooled, diluted with petroleum ether, and filtered from a small amount of unreacted maleic anhydride admixed with a proportion of the desired mono ester.

Thesolvent was removed from the filtrate by vacuum distillation at 50-60/7 mm. The residue was a clear yellow oil, neutralization number 124, saponification number 269. Determination .of the hydroxyl substituents by Zerewitinofl method of methane evolution gave 59.2 cc. per gram. Assuming that the 2% excess oleyl alcohol employed in the initial charge remains in the finalproduct. and that the 10% of impurities present in the initial alcohol are present as inert ingredients, as they appear to be, the composition of the final crude product would be 89.9% of the desired mono ester, 10.4% inert ingredients, and 1.7% oleyl alcohol. Such a composition would have a neutralization number of 134, a saponification number of 270 and would evolve 55.2 cc. of methane per gram in the Zerewitinoff hydroxyl determination. The crude mono oleyl maleate so obtained was then reacted with ethylene glycol as described below.

The maleic anhydride can be readily, removed from the other solids which precipitate from the reaction mixture by, dissolving the combined solidsiin acetone and then pouringthe acetone solution into a large excess of water. The maleic acid is removed from the water and the water insoluble solids filtered off and combined with the main proportion if desired. The mono oleyl maleate obtained from the water had a neutralization number of 157 as compared to thecalculated value of 153.

Oleyl beta hydroxy ethyl maleate Into a reaction vessel of suitable capacity fitted with a water trapand reflux condenser there was charged substantially 250 parts by weight of mono oleyl maleate, 425 parts by weight of ethylene glycol and benzenesufiicient to provide a. mixture which refluxed at l40- l50 C. The mixture was then heatedat reflux for35 hours while water and glycol werev stripped out. The excess glycol and. solvent Werethen removed by vacuum distillation up to 169/4 mm. Theresiduewas diluted with asolvent, as for. example petroleum ether,.and'filtered through alayer of clay, washed thoroughly and the solvent removed by vacuum distillation. The residue was a yellow brown oil comprising oleyl beta hydroxy ethyl maleate which by the Zerewitinoff hydroxyl determinationgave 65.2 cc. methane per gram. It was reacted with maleic anhydride as described below employing that amount of the anhydride'required to react with the hydroxyl groups actually present as determined by the aforementioned analysis.

EXAMPLE II Oleyl beta hydroxy ethyl maleate 189-.3 parts by weight, and maleic anhydride, 52.4 parts by Weight, were admixed in a suitable reaction vessel and stirred and heated at 50-60 C. for twenty-four hours. The product was a clear yellow brown oil readily soluble in mineral oil fractions which was believed to comprise mainly the mono oleyl'ester of ethylene di-acid maleate.

EXAMPLE III Into a reaction vessel of suitable capacity fitted with a water trap and reflux condenser there was charged 31 parts by weight of ethylene glycol (substantially 0.5 molecular proportion) and 100 parts by weight of succinic .anhydride (substantially 1.0 molecular proportion). The mixture was warmed slightly whereupon a vigorous reaction set in. Cooling was applied to keep the temperature below 170 C. and then after the 5 vigor of the reaction had subsided, stirring and heating were continued for two hours at 150 C. 268 parts by weight (substantially 1.0 molecular proportion) of oleyl alcohol was added together with a quantity of benzene suflicient to impart .110 a temperature of reflux within, the range of 128-148 C. The mixture was heated at 128-148 C. for seventeen and one-half hours during which time the water formed as a by-product of the esteriflcation was removed from the reaction-.15 zone. The solvent was removed by distillation under reduced pressure and the residue treated with 6 parts by weight of calcium carbonate and 10 parts by weight of Attapulgus clay and filtered. The clear oil was again dissolved ina so solvent such as petroleum ether and again clay treated after which the solvent was topped out by heating up to 120 C. /45 mm. The product so obtained was an oily liquid readily soluble in mineral oil fractions and was believed to comprise mainly the di oleyl ester of ethylene di-acid succinate.

Mono octyl succinate Into a container of suitable capacity there was charged 81.7 parts by weight (substantially 0.817 molecular proportion) of succinic anhydride and 106.3 parts by weight (substantially 0.817 molecular proportion) of Z-ethyl hexanol. A quantity of benzene was added sufiicient to provide a refluxing temperature of about 105 C. and the mixture was heated at refluxing temperature for six hours and the solvent stripped out by heating to 153 C./10 mm. The residue was diluted with petroleum ether, filtered, and the solvent again removed as described. The residue was a white waxy solid which had a neutralization number of 234 as compared to a calculated value of 244. The gas evolved in the Zerewitinoff method for determination of hydroxyl groups was 98.3 cc./g. as compared to a calculated value of 45 97.5 cc./g.

Octyl beta hydroxy ethyl succinate Mono octyl succinate, 169 parts by weight, and ethylene glycol, 456 parts by weight, were mixed with benezene suflicient to impart a refluxing temperature of 140-150 C. The mixture was heated at refluxing temperature for about fortytwo hours during which time water and excess glycol were gradually removed. The residue was dissolved in benzene, filtered through a bed of clay and the solvent stripped out by heating at 95/5 mm. The resulting product had a neutralization number of 4.3.

EXAMPLE IV Octyl beta hydroxy ethyl succinate prepared as described above, 134.1 parts by weight, and succinic anhydride, 40 parts by weight, were heated at 100-110 C. for twenty-four hours. The 65 resulting reaction product was a clear orange brown liquid believed to comprise mainly the mono octyl ester of ethylene di-acid succinate.

Mono octadecyl succinate Mono octadecyl succinate was prepared by heating 273 parts by weight of octadecyl alcohol, 100 parts by weight of succinic anhydride and a small amount of benzene at 106-107 C. for eight and one-fourth hours.

octadecyl beta hydrowy ethyl, succinate;

332 parts by weight of the above mono octadecyl succinate, 640 parts by weight of ethylene glycol and a little toluene were heated twentyeight hours at 149-160 C. under reflux with a water separator. The top layer was then separated and the solvent stripped out by heating up to 157 C./1 mm. The resulting product had a neutralization number of zero. It evolved 53.5 c'cl/g. of'metha'ne'by the Zerewitinoff method of hydroxyl determination as compared to a calculated value of 54.2 cc./g.

EXAMPLE V 127.5 parts by weight of the above octadecyl beta hydroxy ethyl succinate and 30 parts by weight of succinic anhydride were heated at 104-1 22 C. for twenty and one-half hours. The reaction mixture was dissolved in ether, the ether solution filtered and. cooled and the product filtered off. The white crystalline product, M. P.

62-63 C., had a neutralization number of number of 91.3. The calculated value is 109. This product was believed to comprise mainly the mono octadecyl ester of ethylene di-acid succinate.

Oleyl beta(beta hydroxy ethoxy) ethyl succinate 324 parts by weight of mono oleyl succinate, 1000 parts by weight of diethylene glycol and toluene suflicient to regulate the temperature were heated for twenty-six and three-fourths hours at 170-175 C. under reflux with a water separator. Water was added and the bottom layer drawn off and discarded. The upper layer was washed repeatedly with water to remove the diethylene glycol and finally heated to C./2

EXAMPLE VI The above product, 137 parts by weight, and succinic anhydride, 30 parts by weight, were heated twenty and one-half hours at 103-ll2 C. The reaction mixture was dissolves in petroleum ether, filtered, and the solvent removed by distillation. The light amber residue partially solidified on standing. This product was believed to comprise the mono oleyl ester of 2,2 oxybisethanol di-acid succinate.

Allyl beta hydroxy ethyl succinate Mono allyl succinate was prepared by reacting allyl alcohol and succinic anhydride. 313 parts by weight of the mono allyl succinate so prepared, 1500 parts py weight of glycol and a small amount of benzene were heated eight hours at 135-148 C. under reflux with a water separator after which time the neutralization number of the reaction mixture was 2.1. Most of the solvent was removed by distillation and the residue after cooling to 60 C. was filtered through a bed of Attapulgus clay. The filtered product was then heated at 148 C./1 mm. to remove the remainder of the solvent.

EXAMPLE VII 70 parts by weight of the above allyl beta hydroxy ethyl succinate and 30 parts by weight of succinic anhydride were heated at 103-120 C. for five and one-half hours. No succinic anhydride sublimed out upon heating at C./1 mm. The reaction product was believed to comprise the allyl ester of ethylene di-acid succinate.

The new polyesters have a variety of industrial uses. They are valuable for compounding tur- 5 bine oils to impart rust inhibiting properties and 7 such use disclosed and claimed in myco-pending application 1 Serial .No. 739,247 fi1ed.,Apri1 3, 1947, now Patent 'No..2,497,432. In addition, they areuplasticizers for rubber. and resins.

Although the invention has been described and illustrated with .respect to certain preferred exwhere R is an unsaturated alkyl radicalcontaining 18-22 carbon atoms, wheremis an even number less than 5, and where R is a divalent aliphatic chain selected from the group consisting of -C2H4 and C2H4OC2H4.

where 1: is an even number less than 5.

43. An-ester of thestructure REFERENCES .CITED The :fdllowing references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,075,107 Frazier p Mar. 30, 1937 v2,295,165 DeGroote et al., Sept. 8, 1942 2,415,366 Muskat' Feb. 4, 1942 2,497,432 .Blake Feb. 14, 1950 2,497,433 Blake Feb. 14, 1950 

1. AN ESTER OF THE STRUCTURE 